56 Reynolds's System.
57 Quoted by Peter, loc. cit., p. 280.
The toughness of the hypertrophied muscle is due to the increase in the connective tissue, which is more marked as a rule in the right than the left ventricle. Sometimes, indeed, it is not at all noticeable in the latter, which may be soft and tears readily with the finger.
SYMPTOMS.—Hypertrophy is a conservative process, usually secondary to some valvular or arterial lesion, and is not necessarily accompanied by any symptoms. So admirable is the adjusting power of the heart that, for example, an advancing stenosis of aortic or mitral orifice may be for years perfectly counterbalanced by a progressive hypertrophy, and the subject of the affection be happily oblivious to the existence of heart trouble. Particularly is this the case with mitral stenosis and the consequent hypertrophy of the left auricle and right ventricle. While leading quiet lives and not straining the heart with violent exertion, such persons may not suffer in any way, or perhaps only experience a little shortness of breath when going up stairs. Indeed, the hypertrophy is in almost all instances an unmixed good, and many of the symptoms which arise are to be attributed to its failure, or, as we say, disturbance of compensation.
The left ventricle is most often involved, and the clinical features of hypertrophy are best seen when it is affected. Inspection may reveal decided bulging of the præcordia, producing in extreme instances marked asymmetry of the chest. This is most frequent in persons under twenty years of age, and it may occur without any pericardial adhesions, which Shroetter58 thinks are invariably associated with this condition. The intercostal spaces may be widened, and the area of visible impulse is much increased. On palpation the character and position of the apex-beat give most important results. It is stronger, more forcible and heaving, and may lift the chest-wall. With each systole the hand or the ear applied over the heart may be visibly raised. A slow heaving impulse is one of the best signs of simple hypertrophy; when there is large dilated hypertrophy the forcible impulse is often more sudden and abrupt. A second, weaker, impulse can sometimes be felt, due possibly (as Gowers suggests) to a rebound from the aortic valves. The area of impulse is greatly increased, and the beat may be felt in the sixth, seventh, or eighth interspace from an inch to three inches outside the nipple. The downward dislocation of the apex is an important sign in hypertrophy of the left ventricle; simple outward displacement may be due to enlargement of the right ventricle.
58 Ziemssen's Encyclopædia, vol. vi.
In moderate grades of hypertrophy, as seen in chronic Bright's disease, the apex-beat may be in the sixth interspace in the nipple-line or a little outside it.
Percussion gives an area of increased dulness, due to the much larger portion of the heart which comes in contact with the chest-wall. The dulness in the parasternal line may begin at the third rib or in the second interspace, and the transverse limits extend from half an inch to two inches beyond the nipple-line, and an equal distance beyond the middle line of the sternum. The dull region is more ovoid than in health. When carefully delimited and measured, there may be in the colossal hypertrophy of aortic valve disease an area of dulness from seven to eight inches in transverse extent. In moderate grades a transverse dulness of four inches is not uncommon.
On auscultation the heart sounds, when there is no valve disease, may not present any special changes, but the first is often prolonged and dull; but when there is dilatation as well, it may be very clear and sharp. Reduplication is not uncommon, particularly in the hypertrophy of renal disease. A peculiar clink—the tintement métallique of Bouillaud—may sometimes be heard, with the impulse most frequently just to the right of the apex-beat. The second sound is clear and loud, sometimes ringing in character or reduplicated. When the hypertrophy depends upon valvular lesions the sounds are of course much altered, and replaced or accompanied by murmurs.
The pulse of simple hypertrophy not dependent on valvular lesions is usually firm, full, and strong, of high tension, and regular. It may be increased in frequency, but often is normal. In eccentric hypertrophy the pulse is full, but softer, and usually more rapid. So long as the hypertrophy is maintained the pulse is regular; one of the earliest signs of failure and dilatation is irregularity and intermittence. The various modifications of the pulse in connection with valve disease are considered elsewhere.